Grip tightening device for pipe wrenches



Jam. 1, WW G. H. CLARK GRIP TIGHTENING DEVICE FOR PIPE WRENCHES FiledJan. 30

m 1K 0A mm n 6w. H e wn w EM 6 Y Patented Jan. EL 1950 GRIP TIGHTENINGDEVICE FOR PIPE WRENCHES George H. Clark, Yakima, Wash. ApplicationJanuary 30, 1948, Serial No' 5,281

2 Claims.

My invention relates to grip tightening devices for pipe wrenches and ofthe type forming the subject matter of my United States Letter PatentNumber 2,377,612, dated June 5, 1945, and over which the instantinvention is designed as an improvement.

The primary object of the instant invention is to provide in, a wrenchhaving a slidable fulcruming jaw, a device of simple form andinexpensive construction operated by squeezing action of the hand on thewrench handle to swing the swingable jaw toward the relatively fixed jawso as to tighten the grip on the work and then look the swingable jaw soas to hold the jaws in tightened gripping relation.

Another object is to provide a device of the character and for thepurpose above set forth adapted for attachment to conventional types ofpipe wrenches without necessitating material change in the basicstructure of such wrenches.

Other and subordinate objects, together with the precise nature of myimprovements, will be readily understood when the succeedingdescriptions and claims are read with reference to the drawingaccompanying and forming part of this specification.

In said drawing:

Figure 1 is a view in side elevation, partly broken away and shown insection, of one type of pipe wrench equipped according to my inventionin a preferred embodiment thereof, with the grip tightening devic'eunlocked;

Figure 2 is a view in side elevation of the same with the griptightening device locked;

Figure 3 is a view in horizontal section taken on the line 3-3 of Figure1 and drawn to a larger scale;

Figure 4 is a fragmentary view in side elevation illustrating a modifiedembodiment of my grip tightening device applied to another type of pipewrench with the device unlocked;

Figure 5 is a similar view with the grip tightening device locked.

Referring to the drawing by numerals, and first to Figures 1 to 3, myimproved grip tightening device is shown therein, in a preferredembodiment thereof, as applied to a conventional pipe wrench having theusual bar handle I with a fixed jaw 2 on the inner end thereof and arear, edge, integral guide sleeve 3 at said inner end in which the usualtoothed shank 4 of a swingable jaw 5 is slidable for pro-setting of theswingable jaw and fulcrumed to swing the swingable jaw toward the fixedjaw. The usual knurled adjusting nut 6 for sliding said shank 4 isconfined between the sleeve 3 and a grooved guide lug l on the rear edgeof the handle I.

The grip tightening means, in the preferred embodiment thereof,comprises an elongated lever B at the front edge of the handle i with apair of lateral edge ears 9 at one end thereof straddling the handle land pivoted thereto, as at 153, opposite the nut 6 so that said lever isswingable toward and from the front edge of said handle l. An end notchI l in the lever B engages the handle I to limit swinging of said lever8 away from said handle. The lever 8 is adapted to engage the handle Ito limit swinging movement of the lever toward said handle.

A U-shaped pusher member [2 straddles the rear edge of the handle ibetween the guide sleeve 3' and the guide lug l, and is slidable,trans-- versely of the handle 5, toward and from said nut 5 opposite thepivot it of the lever B. A pair of links l3 on opposite sides of thehandle I are pivoted at corresponding ends thereof, as at M, to oppositesides of the pusher member 12, and at the other ends thereof arepivoted, as at !5 to the ears 9 in spaced relation to the pivot I0.

As shown in Figure l, in the limit of swinging movement of the lever 8away from the handle i, the links i3 are pulled in a direction to pullthe pusher member I2 toward the rear edge of the handle 1 away from andclear of the nut 6 whereby the grip tightening device is unlocked andthe nut 5 can be adjusted to slide the shank 4 and preset the swingablejaw 5 into approximate gripping relation to the fixed jaw 2. As shown inFigure 2, by swinging the lever 8 toward the handle I, the links l3 arethrust against the pusher member l2 to push the same against the nut 6until the lever 8 assumes its limit of swinging movement toward thehandle I, and in that limit of movement of said lever 8, the pivot l5swings past dead-center relation to the pivots it, and it]. Thus the nut6 is pushed by the pusher member l2 to swing the shank 4 and so as tocause the swingable jaw 5 to be moved from its preset position towardthe fixed jaw 2 to tighten the grip on the work, not shown, and thetightening device is locked in grip tightening position with the pushermember 12 forced into friction locking engagement with the nut 6 toprevent the same from being turned until the grip tightening device isunlocked.

In the modified embodiment of the invention shown in Figures 4 and 5, agrip tightening device similar to that previously described has beenshown as applied to the conventional stillson wrench in which the sleeveI6 for the shank ll of the swingable jaw I8 is pivoted on the handle [9,as at l9, and a nut 20 for adjusting the shank l1 works in an opening 2!in said sleeve. In this embodiment, a lever 22, corresponding to lever8, is pivoted at 23 to the handle l9 and to a pair of links, one ofwhich is shown at 24 and corresponds to a link 13, and which is pivotedto the lever 22 at 25. However, in this instance, the links 24 arepivoted at 26 directly to the sleeve I 6 so as to swing the same aboutthe pivot 19' and thereby swing the shank I! so as to move the swingablejaw 18 toward the fixed jaw 21, the pivots 25 of the links 24 assuming apast deadcenter relation to pivots 23, 26, to lock the grip tighteningdevice when the lever 22 engages the front edge of the handle 19.

The foregoing will, it is believed, sufiice to impart a clearunderstanding of my invention, without further explanation.

Manifestly, the invention, as described, is susceptible of modification,without departing from the inventive concept, and right is hereinreserved to such modifications as fall within the scope of the appendedclaims.

Having described my invention, what is claimed as new is:

1. In a wrench, a handle having a fixed inner jaw on one end and havingfront and rear sides, a swingable outer jaw having a screw threadedshank on one end of which said outer jaw is formed; a bracket on therear side of the handle and adjacent said inner jaw for mounting saidshank for sliding and rocking movement in a plane passing through saidhandle, whereby the other end of said shank can be rocked away from saidhandle to swing the outer jaw toward the inner jaw; a second bracket onthe rear side of the handle and spaced from said shank-mountin bracket;a nut threaded on said shank for slidably adjusting said outer jaw, saidnut being loosely mounted near the rear side of the handle and betweensaid brackets; a U -shaped pusher member straddling the rear side of thehandle between said brackets and between the handle and said nut, saidpusher member being movable against said nut to swing said shank; alever pivotally mounted on the front side of said handle; and operatingconnections between said lever and pusher member for moving the pushermember against said nut and into frictionally locking engagementtherewith.

2. The combination of claim 1 wherein said operating connectionscomprise links pivoted to said lever and pusher member to form a pastdead center look when said pusher member is moved into frictionallylocking engagement with said nut.

GEORGE H. CLARK.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 451,991 Abbots May 12, 18911,291,940 Lee Jan. 21, 1919 1,848,793 Nelson Mar. 8, 1932 2,377,612Clark June 5, 1945 2,436,497 Snell Feb. 24, 1948

